Differential pressure fill-up shoe



Nov. 6, 1962 c. c. BROWN 3,062,296

DIFFERENTIAL PRESSURE FILL-UP SHOE Filed Dec. 1. 1960 2 Sheets-Sheet l c Q I k i? (3 37 44 '43 A 1 42 I f I I I m j; "111"||| A7 56', i 56 E. v

E 57 J z 8 x4 J7 I j INVENTOR.

Nov. 6, 1962 c. c. BROWN DIFFERENTIAL PRESSURE FILL-UP SHOE 2 Sheets-Sheet 2 Filed Dec. 1, 1960 INVENTOR. C. C. Brown BY Fatented Nov. 6, 1962 3,062,296 DIFFERENTIAL PRESSURE FILL-UP SHGE Cicero C. Brown, Brown Oil Tools Inc., P1). Box 19236, Houston, Tex. Filed Dec. 1, 1960, Ser. No. 73,123 12 Claims. (Cl. 166-225) This invention relates to improvements in a combination fill-up shoe and back-pressure valve for attachment to a well casing being run into a well bore.

In running casing in a well bore it is desirable to run the casing into the well as rapidly as possible to reduce the danger of caving of the bore wall and other conditions which might prevent effective introduction of the casing throughout the length of the well bore. However, to guard against blowouts due to high pressure in the earth formations, it is necessary ordinarily to equip the lower end of the casing with a back-pressure valve. This, however, has the eflfect that the casing so-closed will act as a piston, putting undesirable back-pressure against the well bore fluid, driving the fluid, usually mud, into the earth formations, particularly those containing the soughtfor oil and gas. When the casing is in place, it is normally secured in the well bore and sealed off by pumping cement through the back-pressure valve and around the casing to close-off the annulus between the casing and the bore wall of the well. This, of course, requires that the back-pressure or cementing valve be easily opened to permit the discharge of cement when that operation is conducted.

Moreover, in running in the casing, the downward movement must be interrupted frequently to add, sections of the casing. Accordingly, when the casing is equipped with a back-pressure valve, the latter must be constructed to open each time the casing is moved downwardly and to close when the downward movement is stopped. Further, it is desirable that the level to which the casing fills up at each interval of movement be limited to avoid spill-over of the mud fluid with its undesirable conse quences to the men on the rig floor.

There have been various types of fill-up shoes with cementing valves incorporated therein to meet the conditions such as those outlined above. Examples of such devices are disclosed in my US. Patent No. 2,698,054. However, most prior to devices have been relatively complicated in construction and subject to numerous difficulties in actual operation under the conditions frequently encountered in a well bore.

The present invention has for its principal object the provision of a combination fill-up shoe with back-pressure or cementing valve which is relatively simple in construction and which overcomes most of the operating difficulties to which more conventional types of fill-up shoes are subjected.

A more specific object is the provision of a fill-up shoe employing valve mechanism operable in response to differential pressure between the fluid levels inside and outside the casing for opening the back-pressure valve during running-in operations and which includes means by Which the back-pressure valve may be effectively held in closed position once running-in and cementing operations have been completed.

A further object is to provide a fill-up shoe in which the differential pressure controlling the opening of the back-pressure valve may be varied, thereby varying the height to which the fluid level inside the casing may rise before the back-pressure valve closes.

Other and more specific objects of this invention will become apparent from the following detailed description when read in conjunction with the accompanying drawing which illustrates a useful embodiment in accordance with this invention.

In the drawing:

FIG. 1 is a longitudinal, quarter-sectional view of the fill-up shoe with the valve elements shown in their initial positions preparatory to running of the device in a well;

FIGS. 2, 3, 4 and 5, are views similar to FIG. 1 but showing the valve elements in the positions occupied at various stages of operation of the device; and

FIGS. 6, 7, 8 and 9 are partly-sectional perspective views of several of the parts of the device.

Referring to the drawing, the shoe comprises a generally tubular body 19 having a bore 11 and formed at its lower end to provide a rounded nose portion 12, the Wall of which is pierced by a plurality of ports 13. The center of nose portion 12 is formed with a short and inwardly extending tubular boss 14 having an axial opening 15 therethrough. The upper end of body 10 is externally threaded at 16 for connection to a section of well casing C on which the shoe is run into the well. Body 10 is counterbored from its upper end at 17 to form the upwardly facing internal shoulder 18 at a point a short distance above the inner ends of ports 13. A sea-t ring 19 is slidably mounted in counterbore 17 above shoulder 18, the latter forming a stop limiting downward movement of the seat ring. A seal packing 20, such as a conventional flexible O-ring, is seated in a groove 21 provided in the outer periphery of seat ring 19 to extend therefrom into slidable sealing engagement with the wall of counterbore 17 Seat ring 19 is formed with an upstanding tubular neck 22 which is smaller in external diameter than the seat ring, thereby providing the annular space 23 between the exterior of neck 22 and the wall of counterbore 17. Seat ring 19 and neck 22, together, have an axial bore 24, the lower edge of which is downwardly and outwardly tapered or flared to form a valve seat 25. Neck 22 is provided with a pair of diametrically spaced vertical slots 26, 26 opening to the upper end of neck 22 and extending downwardly to a point near seat '25. A keeper ring 27 slidably surrounds neck 22 and is positioned in space '23. A cylindrical stop bar 28 extends diametrically across keeper ring 27 and has its opposite ends fixedly secured in the latter. The stop bar is receivable in slots 26, 26 and has a diameter less than the depth of slots 26, whereby a limited amount of relative vertical movement between seat ring 19 and keeper ring 27 may occur for purposes to be described hereinafter. A split snap ring 29 (see FIG. 7), of conventional resilient construction, is seated in a groove 30 provided in the outer periphery of keeper ring 27. The upper end of snap ring 29 is cut square to form a flat or square upper end 31. A locking groove 32 is formed in the wall of counterbore 17 spaced a short distance above shoulder 18 and is adapted to receive snap ring 29 when the latter is brought in registration therewith. The shape of groove 32 is generally complementary to that of the snap ring (FIG. 9), having its upper end wall 33 square cut to be engaged by upper end 31 of the snap ring. It will be seen that when snap ring 29 is in groove 32, the engagement of the square cut surfaces of end 31 and wall 33 will prevent upward movement of the keeper ring in the body. Upward movement of seat ring 19 will then be limited to the distance between the bottoms of slots 26 and the bottom of stop bar 28.

A latching sleeve 35 is slidably mounted in counterbore 17 above seat ring 19. Latching sleeve 35 has an axial bore 36, the upper end of which tapers upwardly and outwardly to form a valve seat 37. A seal packing 38, such as a conventional O-ring, is seated in a groove 39 provided in the outer periphery of the latching sleeve near its upper end and arranged to project from the groove into sliding engagement with the wall of counterbore 17. A split snap ring 40, of conventional resilient construction, is seated in a groove 41 provided in the outer periphery of latching sleeve 35. A plurality of vertically disposed coil springs 42 are positioned in circumferentially spaced relation between the lower end of latching sleeve and the upper end of neck 22 of seat ring 19 to normally urge these members apart. The ends of the springs are seated in sockets 43 and 44 in seat ring 19 and latching sleeve 35, respectively.

Snap ring has a square cut upper end surface 45 which its lower outer edge is chamfered at 46. Snap ring 40 is adapted to be received in an upper or a lower one or" two latching grooves 47 and 48, respectively, provided in the wall of counterbore 17 in vertically spaced relation to each other, both located above locking groove 32. Upper locking groove 47 has a square cut upper end wall 49 and a downwardly and outwardly tapered lower end wall 50. Lower locking groove 48 has a square cut upper end wall '51 and a downwardly and outwardly tapered lower end wall 52. With this arrangement, it will be seen that when snap ring 40 enters either groove the square cut upper end surface 45 of the snap ring will be engaged with the square cut upper end wall 49 or 51, as the case may be, and thereby prevent upward movement of the latching sleeve relative to body 10. However, when snap ring 40 is locked in upper latching groove 47, for example, and downward pressure is exerted against the upper end of the latching sleeve, the camming action between lower end wall 50 and chamfered surface 46 on the snap ring will compress the latter so that the continued downward pressure will force the snap ring out of groove 47 and move the latching sleeve downwardly in body 10. When the latching sleeve has moved downwardly a sufficient distance to bring the snap ring in registration with groove 48, the snap ring will expand and latch into this groove and hold the latching sleeve against upward movement from its lower position in body 10.

Body 11 is provided interiorly thereof with a plurality of vertically disposed, radially inwardly extending ribs which are circumferentially spaced about the interior of the body between ports 13 to provide a cage for guiding a ball valve 56 enclosed in the bore of body 10 between boss 14 and seat 25. A coil spring 57 is mounted about boss 14 and in compression between the inner wall of nose 12 and ball valve 56 to normally urge the latter upwardly against seat 25 to the position closing bore 24 through the seat ring.

The device is operated as follows, reference being had particularly to FIGS. 1 to 5. In FIG. 1 the parts of the shoe and the valve elements contained therein are shown in the positions occupied when the casing carrying the shoe is first introduced into the well bore. At this stage it will be noted that snap ring 29 is locked in groove 32, while snap ring 40 is locked in upper groove 47, holding latching sleeve 35 in its upper position. The pressure of springs 42 will be urging seat ring 19 down against shoulder 18 in which position stop bar 28 will be located about midway along the length of slots 26. In this position, with ball valve 56 being urged against seat 25 by spring 57, the valve will be spaced slightly below stop bar 28.

As the casing and shoe are run into the well through the mud or other well fluid which will normally be present, the latter will flow through ports 13 and exert upward pressure against the lower end of seat ring 19 (FIG. 2). Upward movement of the seat ring will be permitted by the clearance between stop bar 28 and the bottom of slots 26, snap ring 29 continuing to be held in locking engagement in latching groove 32. This upward movement of seat ring 19 will compress coil springs 42 and will, at the same time, raise seat 25. This will allow ball valve 56 to move upwardly under the pressure of coil spring 57 and the fluid pressure until it engages stop bar 28. Since seat 25 has moved upwardly relative to stop bar 28, ball valve 56 will be held away from seat 25, thereby providing a space between the ball valve and seat 25, thereby providing a space between the ball valve and seat 25, which will effectively open the valve to the flow of fluid through bores 24 and 36 of neck 22 and latching sleeve 35, respectively, thereby allowing casing C to fill up with fluid as it descends in the well bore.

The entering fluid will act on the effective area of seat ring 19, namely, the annular area defined between the outer periphery of O-ring 20, and the circular line of contact of ball valve '56 on seat 25. This area and the force of springs 42 will determine the differential pressure required to close-off bore 24, which will, in turn, determine the height to which the casing will fill up with fluid. When the head of fluid inside the casing plus the compressive force of springs 42 exceeds the head of fluid outside the casing, seat ring 19 will be forced down against shoulder 18, thereby permitting valve 56 to close off bore 24. It will be seen, therefore, that by varying the strength of springs 42, any desired pressure differential may be established between the internal and external column of liquid so that the height of the column of liquid inside the casing can be effectively regulated. Since the springs 42 effectively substitute for liquid head, the level of liquid inside the pipe can be held down to whatever level will assure against slopping-over of liquid from the upper end of the casing, when lowering of the latter is stopped to add a section of easing. With this arrangement, the casing can be run into the well as rapidly as new joints can be connected into the string, without exerting undue piston action on the earth formations, and without causing slopping-over of well liquids from the casing. Moreover, the well will be under full control against blowouts at all times because as soon as the external pressure exceeds the pre-set differential, valve 56 will close.

When the casing has reached the point at which cementing or other operations are to be conducted, the cement or other fluid will be pumped down through the bore of the casing and will exert downward pressure against seat ring 19 and ball valve 56, forcing the latter downwardly against the end of boss 14 and moving seat ring 19 back against shoulder 18 (FIG. 3). With ball valve 56 moved downward against boss 14, a passageway will be provided through seat 25 through which cement or other fluid will flow for discharge through ports 13 into the well bore. Keeper ring 27 and latching sleeve 35 will remain in the same positions they initially occupied, snap rings 29 and 4t) being locked in grooves 32 and 47, respectively.

When cementing or other fluid-introducing operation is completed and it is desired to permanently close the bore of the casing against backflow, a ball valve 60, indicated in broken lines in FIGS. 4 and 5, or other conventional plugging element, will be pumped or dropped through the bore of the casing and brought into contact with seat 37 of the latching sleeve in order to close off bore 36. Closure of bore 36 will cause the pump pressure applied to the fluid inside the casing to be transmitted to latching sleeve 35 and this downward pressure will, in turn, be transmitted to snap ring 40 and force the latter out of groove 47 through camming action of the surfaces 46 and 50, thereby releasing the latching sleeve for downward movement. This movement will continue until snap ring 40 has moved to a position opposite lower groove 48, whereupon the snap ring will expand and enter the latter groove and lock the latching sleeve in its lowered position against upward movement. The downward movement of the latching sleeve will act through the compression of springs 42 to urge seat ring 19 to its downward position against shoulder 18 (FIG. 4). The distances between the parts will be so arranged that when snap ring 40 is received in lower groove 48, the lower end of latching sleeve 35 will be substantially in abutting engagement with the upper end of neck 22 of the seat ring. Thus, the latter will be held in its downward position so that when fluid pressure inside the casing is relieved (FIG. 5), any appreciable upward movement of the seat ring 19 will be prevented by the engagement of neck 22 with the latching sleeve in its lowered position. Whereupon, when the pressure of fluid from inside the Well bore is re-exerted through ports 13, ball valve 56 will be held on seat 25 so that it functions fully as a check valve to prevent reverse flow of fluid into casing C. v

It will be seen that latching sleeve operates, in effeet, as a movable abutment member for springs 42 and seat ring 19, being operable when in its upper position to permit limited upward movement of seat ring 19 relative to shoulder 18, and when in its lower position,

serving to hold seat ring 19 on shoulder 18.

As is generally conventional, the parts employed in the construction of the shoe and its various valve elements will normally be made of easily drillable metallic or plastic materials, so that when it is desired to open the lower end of casing C in connection with the operation of the well, the valve elements and the end portions of the shoe may be readily drilled out to accomplish this purpose.

It will be understood that various changes and modifications may be made in the details of the illustrative embodiment within the scope of the appended claims but without departing from the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

l. A fill-up shoe for a well pipe, comprising, a generally tubular body adapted for attachement to a well pipe and having openings through the wall thereof, an annular seat member movable axially in said body above said openings, spaced apart upper and lower stop means in the body limiting the extent of axial movement of said seat member, the upper stop means being located above the seat member, said seat member having an axial bore, a valve member in the body below said seat member, means resiliently biasing said valve member toward a position closing said bore, said upper stop means carrying means operable in response to relative upward movement of said seat member to engage said valve memher to hold the valve member away from the bore-closing position, an abutment member mounted in said body above said seat member, and spring means arranged between said abutment member and said seat member to bias the latter toward said lower stop means, said abutment member being movable in the body between an upper position permitting axial movement of the seat member between said stop members and a lower position holding the seat member against the lower stop member, and.

cooperable latch means on said abutment member and said body operable to lock said abutment member to said body in one of said upper and lower positions.

2. A fill-up shoe for a well pipe, comprising, a generally tubular body adapted for attachment to a well pipe and having openings through the wall thereof, an annular seat member movable axially in'said body above said openings, spaced apart upper and lower stop means in the body limiting the extent of axial movement of said seat member, the upper stop means being located above the seat member, said seat member having an axial bore, a valve member in the body below said seat member, means resiliently biasing said valve member toward a position closing said bore, said upper stop means carrying means operable in response to relative upward movement of said seat member to engage said valve member to hold the valve member away from the bore-closing position, an abutment member mounted in said body above said seat member, spring means arranged between said abutmentmember and said seat member to bias the latter toward said lower stop means, said abutment member being movable in the body between an upper position permitting axial movement of the seat member between said stop members and a lower position holding the seat member against the lower stop member, and latch means carried by the abutment member cooperating with the body to lock said abutment member in one of said upper and lower positions, said latch means being releasable in re-- sponse to downward pressure on the abutment member to free the latter for downward movement.

3. A fill-up shoe for a well pipe, comprising, a generally tubular body adapted for attachment to a well pipe and having openings through the wall thereof, an annular seat member movable axially in said body above said openings, spaced apart upper and lower stop means in the body limiting the extent of axial movement of said seat member, 'the upper stop means being located above the seat member, said seat member having an axial bore, a valve member in the body below said seat member, means resiliently biasing said valve member toward a position closing said bore, said upper stop means carrying means operable in response to relative upward movement of said seat member to engage said valve member to hold the valve member away from the bore-closing position, an abutment member mounted in said body above said seat member, spring means arranged between saidabutment member and said seat member to bias the latter toward said lower stop means, said abutment member being movable in the body between an upper position permitting axial movement of the seat member between said stop members and a-lower position holding the seat member against the lower stop member, latch means carried by the abutment member, and latch-engaging means positioned on the body at said upper and lower positions, said latch-means and said latch-engaging means having cooperating latching elements operable when engaged to prevent relative upward movement of the abutment member and to be disengaged in response to downward pressure on said abutment member.

4. A fill-up shoe according to claim 3 wherein said latch means comprises a resilient snap ring and said latch-engaging means comprises annular snap ring-receiving grooves in the interior wall of said body.

5. A fill-up shoe for a well pipe, comprising, a generally tubular body adapted for attachment to a well pipe and having openings through the wall thereof, an annular seat member movable axially in said body above said openings, spaced apart upper and lower stop means inthe body limiting the axial movement of said seat member, said upper stop means being located above the seat member, said seat member having an axial bore, a valve member in the body below said seat member, means resiliently biasing said valve member toward a position closing said bore, said upper stop means carrying means operable in response to relative upward movement of said seat member to engage said valve member to hold the valve member away from the bore-closing position, means mounted in said body resiliently biasing the seat member toward said lower stop means, and a movableabutment member releasably secured to the body above the seat member and releasable in response to fluid pressure in thevbody for movement by said fluid pressure to a position holding the seat member against the lower stop member.

6. A fill-up shoe for a well pipe, comprising, a generally tubular body adapted for attachment to a well pipe and having openings through the wall thereof, an annular seat member movable axially in said body above said openings, spaced apart upper and lower stop means in the body limiting the axial movement of said seat member, the upper stop means being located above the seat member, said seat member having an axial bore, a valve member in the body below said seat member, means resiliently biasing said valve member toward a position closing said bore, said upper stop means carrying means operable in response to relative upward movement of said seat member to engage said valve member to hold the valve member away from the bore-closing position, means resiliently biasing the seat member toward said lower stop means, an abutment member disposed in the body above the seat member and movable downwardly in response to fluid pressure to a position holding the seat 7, member against the lower stop member, and cooperable latch means on said abutment member and said body operable to secure the abutment member to said body in said holding position.

7. A fill-up shoe for a well pipe, comprising, a generally tubular body adapted for attachment to a well pipe and having openings through the wall thereof, an annular seat member movable axially in said body above said openings, spaced apart upper and lower stop means limiting the axial movement of said seat member, said seat member having an axial bore, a valve member in the body below said seat member resiliently biased toward a position closing said bore, said upper stop means carrying means operable in response to relative upward movement of said seat member to engage said valve member to hold the valve member away from the bore-closingposition, means resiliently biasing the seat member toward said lower stop means, an annular abutment member disposed in the body above the seat member and movable downwardly in response to fluid pressure to a position holding the seat member against the. lower stop member, a resilient snap ring mounted in the outer periphery of the abutment member, and a snap ring-receiving groove. in the wall of said body to receive said snap ring when the abutment is in said holding position.

8. In a fill-up shoe according to claim 7, a second snap ring-receiving groove in the wall of said body at an. elevation above the first-mentioned snap ring-receiving groove.

9. A fill-up shoe for a well pipe, comprising, a generally tubular body adapted for attachment to a well pipe and having openings through the wall thereof, an annular seat member movable axially in said body above said openings, spaced apart upper and lower stop means in the body limiting the extent of axial movement of said seat member, the upper stop means being located above the seat member, said seat member having an axial bore, the lower end of said bore defining an annular valve seat, a valve member in the body below said valve seat, means resiliently biasing said valve member toward a position closing said bore, said upper stop means. carrying means operable in response to relative upward movement of said seat member to engage said valve member to hold the valve member away from the bore-closing position, an abutment member mounted in said body above said seat member, spring means arranged between said abutment member and said seat member to bias the latter toward said lower stop means, said abutment member being movable in the body between an upper position permitting axial movement of the seat member between said stop means and a lower position holding the seat member against the lower stop means, the force of said spring means being selected to provide a pre-determined pressure biasing said seat member toward said lower stop means, and cooperable latch means on said abutment member and said body operable to secure the, abutment member in said holding position.

0. A fill-up shoe for a well pipe, comprising, a generally tubular body adapted for attachment to a well pipe and having openings through the wall thereof, an annular seat member movable axially in said body above said openings, spaced; apart upper and lower stop means limiting the extent of axial movement of said seat member, said seat member having an axial bore, a valve member in the body below said seat member, means resiliently biasing the valve member toward a position closing said bore, said upper stop means comprising an annular keeper ring concentric with said seat member, latch means carried by the keeper ring securing the same to said body, a bar element extending diametrically across said keeper ring and vertically positioned relative to the seat member to be operable in response to relative upward movement of said seat member to engage said valve member to hold the valve member away from the bore-closing position, means resiliently biasing the seat member toward said lower stop means, and a movable abutment member releasably secured to the body above the seat member and releasable in response to fluid pressure in the body for movement by said fluid pressure to a position holding the seat member against the lower stop means.

ll. A fill-up shoe for a well pipe, comprising, a generally tubular body adapted for attachment to a well pipe and having openings through the wall thereof, an annular seat member movable axially in said body above said openings, spaced apart upper and lower stop means in the body limiting the. axial movement of said seat member, said upper stop means being located above said seat member, said seat member having an axial bore, a valve member in the body below said seat member, means resiliently biasing the valve member toward a position closing said bore, said upper stop means carrying means operable in response to relative upward movement of said seat member to engage said valve member to hold the valve member away from the bore-closing position, and means mounted in the, body resiliently biasing the seat member toward, said lower stop means.

12. A fill-up shoe for a well pipe, comprising, a generally tubular body: adapted for attachment to a well pipe. and having openings through the wall thereof, an annular seat member movable axially in said body above said openings, spaced apart upper and lower stop means in the, body limiting the axial movement of said seat member, said upper stop means being located above the seat member, said seat member having an axial bore, a valve member in the body below said seat member, means resiliently biasing said valve member toward a position closing said bore, said upper stop means carrying means operable in response to relative upward movement of said seat member to engage said valve. member to hold the valve. member away from the bore-closing position, and spring eans mounted in said body resiliently biasing said seat member toward said lower stop means, the force of said spring means being selected to provide a pre-determined biasing pressure on said seat member.

References Cited in the f le of this patent UNITED STATES PATENTS 2,630,178 Brown Mar. 3, 1953 42, 40 Brown June 16, 1953 ,698,05 Brown et, al. Dec. 28, 1954 

